Photographic shutter retarding mechanism



' Sept. 15, 1931. w, RlDDELL 1,823,293

PHOTOGRAPHIC SHUTTER RETARDING MECHANISM Filed Dec. 20. 1929 PatentedSept. 15, 1931 UNITED STATES PATENT OFFICE WILLIAM A. RIDDELL, OFROCHESTER, NEW YORK, ASSIGNOR TO EASTMAN KODAK COM- PANY, OF ROCHESTER,NEW YORK, A CORPORATION OF NEW YORK PHOTOGRAPHIC SHUTTER RETARDINGMECHANISM Application filed December 20, 1929. Serial No. 415,472.

This invention relates to photography and more particularly tophotographic shutters.

One object of my invention is to provide a simple and durable connectionbetween a power drive and a retarding device by which exposures ofvarious durations may be obtained. Another object ofvmy invention is toprovide a lost-motion connection between a driving device and aretarding device which can be readily set. Other objects of my inventionwill appear from the following specification, the novel features beingparticularly pointed out in the claims at the end thereof.

This invention relates to shutters having a retarding device which has avariable relation with a setting device so that the shutter blades maybe made to operate at different speeds as, for instance, is shown inanother form in Patent 1,341,823, Riddell et al, June 1, 1920.

Coming now to the drawings wherein like reference characters denote likeparts throughout Fig. 1 is a front plan view of a shutter with a portionbroken away showing a speed retarding connection constructed inaccordance with and embodying a preferred form of my invention;

Fig. 2 is a fragmentary detail view of the lost-motion connectionbetween the retarding and the driving device in one position;

Figs. 3 and'5 are views of similar parts in different positions;

Fig. 4 is a view of the parts shown in the preceding three figures withthe addition of a tripping lever;

ig. 6 is an enlarged plan view of a retarding member constructed inaccordance with another embodiment of my invention; and

Fig. 7 is a diagrammatic view to illustrate the relation of the settinglever to the movement of the retarding mechanism.

In certain types of shutters a spring is provided for furnishing thepower and this spring is set in advance of each shutter operation. Theseshutters are ordinarily referred to as setting shutters.

In Fig. 1. I have illustrated a setting shutter in which the shuttercomprises a cupshape portion 1, having a flange 2 extending around itsperiphery and a central upstanding flange 3, there being a shutter coverplate 4 extending between the flanges 2 and 3. The upstanding flange 3is ordinarily thliieaded on its inner side 5 to receive a lens ce Theshutter is provided with a spring 6 which surrounds a post 7 and whichengages a lug 8 in such a manner that the post 7 is normally thrust in acounter-clockwise direction. The post 7 carries a plate 9 provided witha lug 10 adapted to engage and rest upon a post 11, the plate 9 alsobeing provided with a stud 12 which is eccentric to the post 7.

Post 7 also carries a setting lever 13, the normal position of rest ofthis setting lever being indicated by I in Fig. 1. In order to tensionthe spring, the lever 13 is moved from the position shown in Fig. 1 tothe position shown in Fig. 4 in which the lever lies in position IV. Inthis position the disk 9, which has also a lug 14 is engaged by the end15 of a trip lever 16 pivoted at 17 and terminating in a handle 18through which the exposure is made. The lever 16 is normally thrustabout its pivot 17 in a clockwise direction by means of a spring 19 Bypressing downwardly upon the lever 18 the end 15 of lever 16 moves awayfrom lug 1 1 and permits the spring 6 to rapidly turn post 7 until lug10 strikes the post 11.

Only a small part of the movement of the setting lever 13 betweenpositions I and IV is utilized in making the exposure. As the lever 13is moved to position II in Fig. 2 the pin 12 slides down an arcuate edge21 of a yoke member 22 which is pivoted at 23 to the shutter cover, theopposite side of the yoke member having a curved face 24. The curvededges 21 and 24 are connected by a short wall 25, the function of whichwill be hereinafter more fully described. As the setting movementprogresses from the position II to the position III shown in Fig. 3, thepin 12 rides past the curved face. 21 into contact with the curved face2 1. It

should be noted that thesefaces are curved differently and the pin 12,in rotating about post 7 has sliding contact with the curved face 24 andmoves the yoke member 22 about its pivot 23 in the direction shown bythe arrow. Continuing the downward move ment of lever 13, it finallycomes to rest latched behind the lever 16 in position IV shown in Fig.4. In this position the pin 12 is at the upper end of the curvedface-'24.

When the trigger 18 is released the lever 13 moves idly about its shaft7 through. roughly about as indicated inFig. 7, at which time the pin 12strikes the short wall 25 and moves the yoke 22 rapidly about its pivot23 until the-pin strikes the curved surface 21 whichis concentric withthepath' of movement of the pin.

In Fig; 5;.in the position shown at V the pin is engaging the short wall25 and is driving't-he yoke member 22. AS the parts move a littlefurther in a counter-clockwise direction, the pin slides idly along thecurved wall 21: and the yoke 22 is not moved until thegnext settingoperation occurs-.

From the diagrammatic showlng of Fig. 7 thelever 13' can be seentomove'the greater part of its total movement idly, that is'to say,the'first and last part of the movement,

- substantially 55 in each case, does notafi'ect Approximately 16 in themiddle of the stroke is the part actually used the exposure;

for retarding the exposure. v

In my copending application, SerialNumber 340,239, filed February 1-5,1929 for Photographic shutter blade actuating mech-,

anism, I have fully shown and: described-v the mechanism bywhich theshutter blades are moved from the master member which,

in this case, is the power driven post 7 Reference may be had to thisapplication for the driving connection between the blades andmastermember; F or the: present application it is only necessary for anunderstanding of the invention to know that, as-

indicated in Fig. 7, a small portion of the operating stroke,asindicated at O is used for opening" the shutter blades, approximately16 is used for retarding the shutter blade-s (where any retardingaction occurs) and a small portion of the movement beyond the retardingaction indicated at C is used to'close the shutter blades;

"The only reason for giving the angular movement of the setting lever 13is that it greatly facilitates describing the invention. In theparticular shutter measured, the angular movement of the setting leverwas as here described but obviously more or less co ld be readilyaCC'OmPlISlIGCl changing the design somewhat without altering theinvention. The portions indicatedat O and C are entirely diagrammaticand do not illustrate the angular movement of the post 7 necessary toaccomplish these movements since the opening and closing movement of theblades is extremely rapid in the order of .002 to .004 of a second. The

time it takes the post 7 to travel the retardbeing provided with a rack40 adapted to mesh with a pinion 41 adapted to turn with a setting dial42. By turning this setting dial the pin 33 may be made tomove throughthe co-operating slots 34 and 32, these in effect being quite similar tothe slotted levers shown in my Patent 1,341,823, above referred to.

The gear segment 30meshes with a gear 43*which may be one gear of a geartrain similar to the showing of my prior patent;

It will be noticed that the slot 34 in the" yoke 22 is of irregularwidth throughout its length, this width being utilized to make thedistance between the graduations'47 on the dialplate 42 equal orsubstantially equal,

as will be more fully described in my copend ing application, SerialNumber 415,473, filed December 20, 1929.

Theoperation of my invention: is as follows. Assuming a 25th of a secondexposure isto be made the dial 42 is set with 25 beneath the pointer 48.The setting lever 13' is-moved from position Ito position IV in whichlever 16 engages the lug 14. By de-- pressing the trigger 1-8', post 7turns rapidly causing pin 12 to'ride idly down over the curved face 24until it strikes-the short wall 25, atwhich time it rapidly moves theyoke 22 upon its pivot 23 until the pin 12 may ride idly up the face 21.Thetime during'w'hich the pin12 will engage the short wall 25, issubstantially a 25th of a second. dial should have been set with thenumeral 2 beneath the pointer 48' this time would be changed to a half asecond since the pin If the 33' would have been moved to a differentposition in the two slots 34 and 32"and thus the leverage of theretarding gear train would have been altered.

In Fig. 6 I have illustrated a second. em-

bodiment of my invention in which the yoke- 122' is-provided with a pairof curved faces 123 which are of substantially the same ra-: dius butwhich have offset centers of curva-- ture'. The short wall here consistsof anotch 124. 'When the; master member is moved so that pin 12' slidesidly 'down: a

face 123 it will engage the notch 124 and turn the yoke 122 u on itspivot.

The advantage 0 having the yoke shaped as shown in the preceding figuresis that the setting movement requires less effort since the yoke 22 ismoved comparatively slowly by the pin 25 striking the curved face 24.The yoke 22 will be moved rapidly when the pin 12 strikes the short wall25, however, so that the operative movement in which the pin 24 movesthe yoke 22 is the same as the operative movement where the pin 120moves the yoke 122 in Fi 6. In the setting movement in Fig. 6, however,the pin 120 engages the notch 124 and moves the yoke 122 more rapidlytowards its set position and as this setting movement is accomplishedagainst the retarding gears it is more difiicult to set a shutter withthe parts constructed as shown in Fig. 6 than it is to set the shutterwith the parts shown as constructed in the other views. If, however,only short retarded exposures are to be made this is not a very materialfeature.

Having thus described my invention, what I claim as new and desire to besecured by Letters Patent of the United States is:

1. In a photographic shutter, the combination with rotatably mountedmaster member, of a retarding device, and a lost-motion connectionbetween the retarding device and master member including a yoke and apin adapted to engage the yoke and being adapted to drive the yoke intwo directions, said pin being carried by the master member.

2. In a photographic shutter, the combination with rotatably mountedmaster member, of a retarding device, and a lost-motion connectionbetween the retarding device and master member including a pivoted yokehaving a plurality of pin engaging surfaces. a pin carried by the mastermember adapted to engage said yoke surfaces.

3. In a photographic shutter, the combination with rotatably mountedmaster mem ber, of a retarding device, and a lost-motion connectionbetween the retarding device and master member including a pivoted yokeincluding arcuate pin engaging surfaces, and a pin carried by the mastermember for enga ing these surfaces.

4. n a photographic shutter, the combination with rotatably mountedmaster member, of a retarding device, and a lost-motion connectionbetween the retarding device and master member including a pivoted yokeincluding arcuate pin engaging surfaces connected to each ot er by ashort wall, and a pin carried by the master member and adapted to engagethe arcuate surfaces and to drive the yoke through engagement with theshort wall.

5. In a photographic shutter, the combination with rotatably mountedmaster member, of a retarding device, and a lost-motion connectionbetween the retarding device and master member including a pivoted okeincluding arcuate pin engaging sur aces on offset centers, and a pincarried by the master member for engaging the arcuate surfaces.

6. In a photographic shutter, the combination with a master member, of arotatably mounted master member, a retarding device including a pivotedyoke having arms embracing the master member and a pin carried by themaster member adapted to engage the arms.

7. In a photographic shutter, the combination with a master member, of arotatably mounted master member, a retarding device including a pivotedyoke having arms embracing the master member and a pin carried by themaster member, the relation of the pin and arms being such that thepivoted yoke may be rocked upon its pivot by the master member throughthe successive engagement of the pin with the arms of the yoke.

Signed at Rochester, New York, this 16th day of December, 1929.

WILLIAM A. RIDDELL.

